There are UV leak detection kits you can purchase at all most any automotive store which have UV dyes, lights and glasses that will help you locate a leak.

First run a vacuum pump on it if available. If not buynsome of the dyes at your local auto zone or likewise.

You answered your own question. It has a leak. There are dyes that can be added to the sytem that will detect the exact location of the leak. You need to seek professional help with this, as you cannot repair the leak yourself in even if you find it.

fluorescent should be used it detects leaks with the help of dyes the dyes can cause strains on the equipment an foerign substance could disprove the warranty.

LBMDOLPH-CHECKMATE SOUNDCLOUD

There are a number of dyes made specifically for this purpose; any of them would work.